DCAudioDIY.com http://dcaudiodiy.com/phpBB3/ |
|
Broskie's Unbalancer http://dcaudiodiy.com/phpBB3/viewtopic.php?f=4&t=2216 |
Page 1 of 3 |
Author: | Stuart Polansky [ March 21st, 2023, 10:11 am ] | |||
Post subject: | Re: Broskie's Unbalancer | |||
More pics
|
Author: | tomp [ March 21st, 2023, 12:42 pm ] | ||||
Post subject: | Re: Broskie's Unbalancer | ||||
A great way to go from balanced to unbalanced or unbalanced to balanced is the use of two devices from THAT corporation. I have used them very successfully in the past and except for high voltage isolation, they have many advantages over transformers. I did a two part article on using them in July of 2009 published in audioXpress. I'm enclosing the PDF files on them and also a layout of the PCB is did. I have the ExpressPCB file for that if anyone wants it. That circuit will convert a stereo signal in either direction.
|
Author: | Stuart Polansky [ March 21st, 2023, 1:16 pm ] |
Post subject: | Re: Broskie's Unbalancer |
I'll read up on those Tom. The Unbalancer doesn't use any signal transformers. I'll post the schematic later. The Izzy Wizzy phono stage has a differential output stage. The plates are connected just like a push pull amp to an interstage transformer. It's been highly praised. We'll see how it sounds, whether the elimination of coupling caps, but the addition of a transformer is better or worse. Stuart |
Author: | SoundMods [ March 21st, 2023, 2:53 pm ] | ||
Post subject: | Re: Broskie's Unbalancer | ||
Stuart Polansky wrote: I'll read up on those Tom. The Unbalancer doesn't use any signal transformers. I'll post the schematic later. The Izzy Wizzy phono stage has a differential output stage. The plates are connected just like a push pull amp to an interstage transformer. It's been highly praised. We'll see how it sounds, whether the elimination of coupling caps, but the addition of a transformer is better or worse. Stuart How about a plain and simple differential input connected through XLRs?
|
Author: | Roscoe Primrose [ March 21st, 2023, 3:00 pm ] |
Post subject: | Re: Broskie's Unbalancer |
If you like the KISS principle, hard to beat at DN2540 and a resistor for a CCS. Even the TO-92 package should be more than robust enough for your application... Roscoe |
Author: | David McGown [ March 21st, 2023, 3:59 pm ] |
Post subject: | Re: Broskie's Unbalancer |
Stuart, Since you are committed to PP amps, the natural thing is to keep everything balanced (differential) to the power amp. No more phase splitter. It makes no sense to convert back to single ended out of the preamp and then split phase again at the amp. I know the OddWatt amps do the phase splitting in the output stage, so it would require a little rework to convert the SRPP driver into a differential, but hey, it is only resistors and perhaps another signal capacitor. But that is a system wide change and upsets everything including interconnects (right after you upgraded to RCA Audio Envy!). You should really look at Allen Wright's designs for a fully differential preamp/amplifier. Some really interesting and good stuff there. All you are doing is executing in vacuum tubes what the Topping does with an opamp when it converts from balanced to SE after the DAC. The most basic circuit is a summing amplifier executed with a single opamp. Maybe the tube circuit will sound better, but maybe not. It is cheap to put something together with what Tom is suggesting. A pair of transformers is another solution that is easy to try without upsetting everything. Jensen and Cinemag makes some. I think I may even have a pair of Cinemag transformers that may work, I will have to dig around. I have been toying with balanced in explorations of powerful versions of First Watt amplifiers (converting a stereo 25W Class A to a 100W monoblock), but have backed off because I realize that (1), I prefer tubes, and (2), a 30W tube amplifier does almost everything I need or want for the music I listen to. David |
Author: | tomp [ March 21st, 2023, 4:13 pm ] |
Post subject: | Re: Broskie's Unbalancer |
Stuart Polansky wrote: I'll read up on those Tom. The Unbalancer doesn't use any signal transformers. I'll post the schematic later. The Izzy Wizzy phono stage has a differential output stage. The plates are connected just like a push pull amp to an interstage transformer. It's been highly praised. We'll see how it sounds, whether the elimination of coupling caps, but the addition of a transformer is better or worse. Stuart Stuart, I wasn't saying the Unbalancer used transformers. It was just a general comment about the parts from THAT corporation compared to transformers. No doubt that transformers have the highest Common Mode Rejection Ration and can isolate higher voltages than ICs, but you have all the audio problems like saturation, leakage inductance, interwinding capacitance, hysteresis, etc. to deal with. The papers by Bill Whitlock mentioned in the data sheets are some of the best when it comes to describing the different approaches to both unbalanced and balanced. I have found in home situations in all the places where I have lived, I never needed to take advantage of the CMRR of balanced circuits. That is more important in industrial situations where there are long runs near many types of electrical equipment. |
Author: | Stuart Polansky [ March 21st, 2023, 6:07 pm ] |
Post subject: | Re: Broskie's Unbalancer |
SoundMods wrote: Stuart Polansky wrote: I'll read up on those Tom. The Unbalancer doesn't use any signal transformers. I'll post the schematic later. The Izzy Wizzy phono stage has a differential output stage. The plates are connected just like a push pull amp to an interstage transformer. It's been highly praised. We'll see how it sounds, whether the elimination of coupling caps, but the addition of a transformer is better or worse. Stuart How about a plain and simple differential input connected through XLRs? That works fine if I wanted balanced out. I may someday. |
Author: | Stuart Polansky [ March 21st, 2023, 6:12 pm ] |
Post subject: | Re: Broskie's Unbalancer |
Roscoe Primrose wrote: If you like the KISS principle, hard to beat at DN2540 and a resistor for a CCS. Even the TO-92 package should be more than robust enough for your application... Roscoe My first thought actually. I have lots. Dave B convinced me to try his solution. It works for him. I had all the parts. BTW, you and I need to talk about Otaris. |
Page 1 of 3 | All times are UTC - 5 hours [ DST ] |
Powered by phpBB® Forum Software © phpBB Group https://www.phpbb.com/ |